Numerical parametric study on wafer cleaning effects by bottom-side impinging jet
하부 충돌 제트에 의한 웨이퍼 세정 효과의 수치적 매개 변수 연구
- 주제어 (키워드) Liquid film , Wafer clean process , Wet etching , Multi-phase CFD simulation , Bottom-side impinging jet , Liquid coverage , Etching rate , Wall shear stress
- 발행기관 서강대학교 일반대학원
- 지도교수 강성원
- 발행년도 2025
- 학위수여년월 2025. 8
- 학위명 석사
- 학과 및 전공 일반대학원 기계공학과
- 실제 URI http://www.dcollection.net/handler/sogang/000000081828
- UCI I804:11029-000000081828
- 본문언어 한국어
- 저작권 서강대학교 논문은 저작권 보호를 받습니다.
초록 (요약문)
This study performs a numerical parametric study on a semiconductor wafer cleaning process with bottom-side impinging jet using 3-D CFD simulations, aiming at reducing defects in semi- conductor manufacturing. By comparing top-side and bottom-side jets under relatively lower rotation speed conditions, gravitationally induced liquid loss is identified. A study on the nozzle diameter shows that a smaller diameter leads to small-scale instabilities from a higher jet velocity, while a larger diameter causes large-scale instabilities due to jet fluctuation from reduced iner- tia. In both cases, liquid detachment and loss increase, indicating that an optimal diameter value exists to minimize the liquid loss. Under relatively higher rotation speed conditions, the flow rate affects the flow field mainly near the rotational center, while the rotational speed dominates the flow field near the bevel. In the bevel region, increased rotation speed reduces the chemical coverage and raises the wall shear stress, showing a trade-off between the chemical and mechan- ical cleaning effects. Examining correlation of three indices for cleaning effects (liquid coverage, wall shear stress, etch rate) presents that the liquid coverage and etching rate show similar pat- terns over space, implying the liquid coverage as an indicator of the etching effect. This study provides with useful data to optimize a bottom-side jet cleaning process with the gravity effect, which can be beneficial to developing the semiconductor manufacturing process.
more목차
1 Introduction 1
1.1 Part 1 1
1.2 Part 2 3
2 Simulation details 6
2.1 Simulation conditions 6
2.2 Numerical methods and governing equations 9
2.3 One-step chemistry of silicon dioxide etching 12
3 Results and discussion 16
3.1 Parametric study of nozzle diameter 16
3.1.1 Comparison of top-side and bottom-side impinging jet 16
3.1.2 Effects of nozzle diameter on liquid film stability 22
3.1.3 Mechanisms of cleaning liquid loss 28
3.2 Parametric study of rotation speed and flow rate 31
3.2.1 Effects of rotation speed and flow rate on flow fields 31
3.2.2 Comparison of liquid coverage on bevel 35
3.2.3 Comparison of wall shear stress on bevel 38
3.2.4 Correlation of indices for cleaning effects 41
4 Conclusions 45
References 47
